The present invention generally relates to reproducing styluses for information signal recording mediums, and more particularly to a reproducing stylus which scans over tracks in a recording medium on which information signals are recorded as variations of geometrical configuration, to reproduce the recorded information signals as variations in electrostatic capacitance, and has a configuration which enables the reproducing stylus to have a long life.
As one example of a system which performs high-density recording and reproduction of information signals such as a video and/or an audio signal to and from a recording medium such as rotary recording medium, there is a system which records and reproduces the information signals as variations in electrostatic capacitance. A rotary recording medium reproduced by this system has a spiral guide groove formed thereon, for guiding a tracing stylus used for reproducing a signal. Along the bottom part of this guide groove, there is formed a track of an information signal which is recorded as a variation of a geometrical configuration. The tracing stylus is guided by this guide groove while tracing the bottom thereof, and thus reproduces the recorded information signal.
On the other hand, the present inventors have made it possible to record and reproduce signals in a system which does not have a guide groove, by providing a system which can perform tracking control of the tracing stylus so that the stylus will trace accurately and positively over the recorded track. In this system, the information signal is recorded on a rotary recording medium as a variation of a geometrical configuration.
However, in the above described system and the system developed by the present inventors, the recording medium must be rotated at a high speed to obtain a high relative linear velocity between the recording medium and the reproducing stylus, in order to perform reproduction with a large signal-to-noise (S/N) ratio. Hence, the reproducing stylus which makes contact with and slides over the recording medium, is easily worn out due to friction. Accordingly, from the practical point of view, a reproducing stylus which does not wear out due to friction even when the stylus is used for a long time, is desired. Further, it is desirable that the reproducing function of the reproducing stylus is not deteriorated even when the stylus is slightly worn out, and that the reproducing stylus does not damage the recording medium.